Designing three-dimensional hierarchical porous chrysanthemum flower-like CoNiFe2O4/carbon spheres as high-performance electrode for supercapacitors and oxygen reduction reaction

Preparation of rambutan-like Co0.5Ni0.5Fe2O4 as anode for high–performance lithium–ion batteries

“…The characteristic peak of Co 0.5 Ni 0.5 Fe 2 O 4 was quite similar to NiFe 2 O 4 and CoFe 2 O 4 without extra lines representing the Co 0.5 Ni 0.5 Fe 2 O 4 has a single-phase and shares the same structure with both NiFe 2 O 4 and CoFe 2 O 4 . The characteristic (311) plane at 2θ of 35.5 also indicating the spinel structure of Co 0.5 Ni 0.5 Fe 2 O 4 sample ( Shehnaz et al, 2021 ). The slight peak shift can be observed in Figure 1B , and the characteristic peak of Co 0.5 Ni 0.5 Fe 2 O 4 was found between NiFe 2 O 4 and CoFe 2 O 4 .…”

“…Compared with NiFe 2 O 4 , the peak location of Co 0.5 Ni 0.5 Fe 2 O 4 moved 0.4-0.8 eV to high binding energy, which attributed to the charge transfer as well as the strong interaction of the Ni-O bond. The Co 2p peaks at about 779.9 and 795.0 eV (Figure 3B) are attributed to Co 2+ and the peaks at 782.2 and 796.7 eV indicating the presence of Co 3+ , which is the result of the partial oxidation of Co 2+ from the surface (Shehnaz et al, 2021). Meanwhile, because of the strong Co-O interaction, the binding energy of The nitrogen adsorption-desorption experiment was conducted to test the specific surface area and pore size distribution of the three samples.…”

“…The 2p 3/2 peaks at about 710.1and 712.4 eV ( Figure 3C ), along with the 2p 1/2 peaks at around 723.4 and 725.3 eV represents the coexist of both the tetrahedral site and octahedral sites Fe 3+ species. The satellite peaks at around 718.1 eV and 733.2 eV, also represent the presence of Fe 3+ cations ( Shehnaz et al, 2021 ). Compared to NiFe 2 O 4 and CoFe 2 O 4 , the binding energy of Ni 2 p and Co. 2 p in Co 0.5 Ni 0.5 Fe 2 O 4 were increased while that of Fe 2 p were decreased, which means the electrons transfer from Ni and Co. to Fe.…”

N, S Codoping and Mesoporous‐Induced Capacitive Storage Enhancement in Supercapacitor and Improved Li–S Battery Performances of Polystyrene Waste‐Derived Carbon Electrode

“…The appearance of the pores would have resulted due to KOH activation. [24] The following reactions are seen to occur during the activation process, leading to porous carbon matrix.…”

“…The increased resistance is attributed to the degradation of the electrode as well as electrolyte due to extensive cycling, as has been reported before. [24,45,46]…”